Journal of Rehabil itation Research & Development Kinematic analysis for determination of bioequivalence of a modified Hybrid III test dummy and a wheelchair user

Abstract—We investigated whether a modified 50th-percentile Hybrid III test dummy (HTD) (First Technology Safety Systems, Plymouth, MI) would have motion similar to a wheelchair test pilot (TP) with T8 paraplegia. Test cases were seated in a Quickie P100 electrically powered wheelchair (Sunrise Medical, Inc., Phoenix, AZ) driven at three speeds (0.8, 1.4, and 2.0 m/s). Three braking conditions—joystick release, joystick full reverse, and emergency power-off—were used to stop the wheelchair. The subsequent upper-body motion was recorded for the creation of kinematic exposure profiles of the wheelchair riders. The maxi-mum concentration (Cmax) and area under the trunk angular dis-placement, velocity, and acceleration curves (AUC0–Cmax) were calculated. Assessments of average, individual, and population bioequivalence were conducted after data were subjected to natu-ral logarithmic transforms. Only the Cmax of the trunk angular acceleration of the HTD and TP was average bioequivalent (0.82–1.04). Both Cmax and AUC0–Cmax measures for all kine-matic exposures between the TP and HTD were individual and population bioequivalent (95 % upper-confidence bound < 0, lin-earized bioequivalence criteria). This indicates that the HTD is a suitable surrogate for a wheelchair user in low-speed, low-impact wheelchair studies